Conventionally, when power absorbed by the human head is measured, a head phantom simulating the dielectric properties of the human head is constructed, power absorbed by the phantom is measured, and power absorbed by the human head is estimated. A measuring method described in non-patent literature 1 or the like has been used. Apparatuses for easily implementing this type of measuring method have also been proposed (patent literature 1 and 2).
Typical conventional art will be described with reference to FIGS. 1 to 3. FIG. 1 is a view showing the placement of components in conventional local average absorbed power measuring methods. FIG. 2 is a view showing the flow of a first conventional local average absorbed power measuring method. FIG. 3 is a view showing the flow of a second conventional local average absorbed power measuring method. In FIG. 1, an antenna 810 of a radio device (not shown) is placed on the y-axis, and a rectangular parallelepiped phantom 920 is disposed a given distance away in the y-axis direction. An electric and/or magnetic probe 910 measures the electric field strength or magnetic field strength of radio waves in a part where the tip is positioned. The phantom may have the shape of the human head. The axes can be oriented in given directions.
In the first conventional local average absorbed power measuring method (FIG. 2), absorbed power is measured at a plurality of measurement points 921mn (m is an integer from 1 to M, and n is an integer from 1 to N) in a two-dimensional plane 921 at a given distance inward from the surface of the phantom 920 on the side of the antenna 810 (S911). Then, absorbed power is measured at a plurality of measurement points in a three-dimensional space 925 that includes the measurement point 921mn where the absorbed power becomes the highest (S912). The measurement points are set at smaller intervals in the measurement in the three-dimensional space 925 than in the measurement in step S911. The size of the small intervals should be determined in accordance with the required measurement accuracy. Then, the average absorbed power in a local place (local average absorbed power) near the point where the absorbed power becomes the highest is obtained (S913).
In the second conventional local average absorbed power measuring method (FIG. 3), the amplitude and phase of the electric field or magnetic field are measured at a plurality of measurement points 921mn (m is an integer from 1 to M, and n is an integer from 1 to N) in a two-dimensional plane 921 at a given distance inward from the surface of the phantom 920 on the side of the antenna 810 (S921). The distribution of absorbed power in the three-dimensional space 925 is calculated by using an equivalence theorem or the like (S922). From the calculated distribution of absorbed power in the three-dimensional space 925, the local average absorbed power is obtained (S923).
To simplify the description given below, the entire processing flow (S911 to S913) of the first conventional local average absorbed power measuring method will be referred to as step S910, and the entire processing flow (S921 to S923) of the second conventional local average absorbed power measuring method will be referred to as step S920.
A local average absorbed power measuring method in patent literature 2 has a determination step, and a local average absorbed power measurement step or a local absorbed power calculation step. In the determination step, measurement points, and a combination of transmission powers and phases of individual antennas or a combination of transmission powers of the antennas are determined in advance, and then, a combination of transmission powers and phases of the antennas or a combination of transmission powers of the antennas for obtaining the local average absorbed power is determined by using the measurement results. In the local average absorbed power measurement step or local average absorbed power calculation step, the local average absorbed power is measured or calculated with the combination determined in the determination step.